It really depends on what you're doing I'd say. If you're doing a lot of heavy multitasking, then you'd be better off with a Phenom II. Or if you do a lot of graphic design or modeling/animation that has you running multiple programs and transferring between them, then again you'd benefit from the quad core setup. But for most single, focused applications, you'll probably see a very slight increase from an e8400 or better Core2.